Hydroformylation--the addition of the elements of formaldehyde across a C-C double bond--is used to produce millions of tons of aldehydes for industrial applications. Despite the low cost and high availability of starting materials, as well as the versatility of the products, hydroformylation has yet to be applied as a general tool in organic synthesis. This is due in large part to a lack of regiocontrol in the reaction; mixtures of linear (n) and branched (iso) aldehyde isomers are often produced. The research plan described herein proposes the use of well-defined Lewis acid-modified rhodium(I) catalysts for highly regio- and enantioselective hydroformylation of functionalized olefins. The chiral nonracemic aldehydes obtained as products of these reactions can be applied to the synthesis of many important biologically active compounds. [unreadable] [unreadable]